最近在做一个寺庙相关信息的大屏显示系统时，由于使用的历史系统后台，跨域问题较难解决，最后决定使用图片流的方式，在前端显示图片。
后端Java如下：
@RequestMapping(value = "/getFileStream", method = RequestMethod.GET)
public void pdfStreamHandler(HttpServletRequest request,
HttpServletResponse response) {
String templeId = request.getParameter("templeId");// 寺庙ID
String propName[] = new String[] { "fileSubordinateId", "fileFrom" };
Object propValue[] = new Object[] { Long.parseLong(templeId), 1 };
List<TempleFile> tfList = templeFileService.queryByProerties(propName,
propValue);
String fileSrc = null;
if (StringUtils.isNotBlank(tfList)) {
for (TempleFile tf : tfList) {
if (tf.getFileType().intValue() == 1) {
fileSrc = tf.getFileSavePath();
break;
}
}
}
try {
File pf = new File(fileSrc);
if (!pf.exists()) {
return;
}
double rate = 1; // rate是压缩比率 1为原图 0.1为最模糊
int[] results = getImgWidth(pf);
int widthdist = 0;
int heightdist = 0;
if (results == null || results[0] == 0 || results[1] == 0) {
return;
} else {
widthdist = (int) (results[0] * rate);
heightdist = (int) (results[1] * rate);
}
Image src = javax.imageio.ImageIO.read(pf);
BufferedImage tag = new BufferedImage((int) widthdist,
(int) heightdist, BufferedImage.TYPE_INT_RGB);
tag.getGraphics().drawImage(
src.getScaledInstance(widthdist, heightdist,
Image.SCALE_SMOOTH), 0, 0, null);
ServletOutputStream fout = response.getOutputStream();
ImageIO.write(tag, "jpg", fout);
fout.close();
} catch (Exception e) {
// 异常处理
}
}
private static int[] getImgWidth(File file) {
InputStream is = null;
BufferedImage src = null;
int result[] = { 0, 0 };
try {
is = new FileInputStream(file);
src = javax.imageio.ImageIO.read(is);
result[0] = src.getWidth(null); // 源图宽
result[1] = src.getHeight(null); // 源图高
is.close();
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
前端代码如下：
<img id="picture" src= "http://XX.XX.XX.XX/sms/bigscree/getFileStream?templeId=15" style="width: 375px;height: 166px;vertical-align: middle; text-align: center;" />';
最后显示如下所示：
